Refrigeration of hygroscopic material



Dec. 8, 1942. A. B. NEWTON 2,304,192

REFRIGERATION OF HYGROSCOPIC MATERIAL Filed Aug. 16 1940 ,2 Sheets-Sheet l lNVE-NTOR Alwin. 13. Nzwi'om ES WM ATTORN EY Dec. 8, 1942.

A. B. NEWTON REFRIGERATION OF HYGROSGOPIG MATERIAL 2 Sheets-Sheet 2 Filed Aug. 16, 1940 V/IIIIIIIIIIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIIIIIIIIIIIIIIIIIIII 1 INVENTOR Alwim CB. N zwl'om' 'IIIIIIIIIIIIIIIIIIIIIIIII ATTORNEY Patented Dec. 8, 1942 REFRIGERATION F HYGROSCOPIC MATERIAL Alwin B. Newton, Minneapolis, Minn., assignor to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a "corporation of Delaware Application August/16, 1940, Serial No. 353,899

Claims.

The present invention relates to means for coolingmaterials containing water and more particularly to means for cooling and freezing food products.

" It isan object .of the present invention to provide means for quickly cooling or freezing materials having an appreciable water content.

' It is also an object of this invention to provide means'for cooling food products by reducing the surrounding vapor pressure thereby causing evaporation of water contained in the product whichevaporation will produce a refrigerating for causingvaporization of a portion of the water.

contained the products.

@Elllthtil objects will be apparent from the accompanying drawings, the specification and from the appended claims. v v

.. In the drawingsz e shows an apparatus for freezing prod- 116128 by means of a power driven air pump and a e t f g l ran;

.Figure 2 shows a manually operable device for cooling products in a container; and

Figure} shows another form of manual device for cooling products in a container.

It has become the practice in recent years to preserve .food products by freezing them when fresh; The frozen product may then be stored or of the currentfmethods is to stack the food in thin layers between plates supplied with a refrigerant. Another method is to spray the product with cold brine. While these methods result in much faster freezing than would be the case if the product was -merely placed in a refrigerated space, the time required is still'rather great'especially in the case ofrneat and vegetables having large volume.

'fThepre'sent invention provides a method of quickly; cooling or freezing food products by causinga refrigerating effect within the product itself 'andf which, therefore, is substantially indeuct. Since the interior of the product is cooled at the same rate asthe exterior, no time is required for heat to be conducted through the product. and the process can be very rapid. The method employed involves reducing the pressure surrounding the product to a point where evaporation of the contained moisture is rapid. Vaporiz'ation of the moisture contained in the product results in abstraction of heatfrom the unvaporized'portion and consequent refrigeration thereof. Since all vegetable products and meats are porous, the pressures at all points within them will remain substantially equal during the procass. This method has been found to be workable, with foods containing very small amounts. of water. The quality of the resulting product is superior due to'the small size of the ice crystals.

In the apparatus illustrated in Figure 1, a 'container ll! of relatively heavy gage material which will bev pressure tight has a plurality of shelves ll suitably supported therein. These shelves ll are adapted to support food products l2 such as meats, vegetables or any other produce containing a substantial amount of water in their structure. 'The container III is closed at the top by a cover I5 and a gasket l6 serves to render the joint between the cover l5 and the container l0 air tight. Wing nuts I8 cooperate with bolts, not shown, to draw the cover l5 tightly against the gasket l6.

Means are provided to remove air and moisture from the container HI including a positive displacement air pump 20 and a centrifugal compressor 2|. A duct or pipe 23 contacts the container Ill with the intake of the centrifugal compressor 2| while a second pipe 24 leads from the pipe 23 to the intake of the air pump 20.

A' water cooled condenser 26 receives the discharge from the c ntrifugal compressor 2|. Cooling water is supplied to the condenser by a supply pipe 21 and'is carried away by' a discharge pipe 28.

the pipes 23 and 24, the centrifugal compressor 2! and the condenser 26 will be filled with air. The centrifugal compressor 2| operating into the pendent of the thickness or volume of the prodcondenser 26 isonly capable of removing con- A valve 30 in the intake pipe 21 serves to control the flow of cooling water to the cona large part of v the volume of the container itself as well as of densible vapors from the container ll so the positive displacement pump II is provided to remove air and other non-condensible gases. when moisture from the food products is present it will be removed by the centrifugal compressor 2|.

An electric motor ll is supplied with power from line wires II and 42. A switch 44 is provided to control the supply of power to the motor II. The motor Ill drives the centrifugal compressor 2] through a belt 46, the air pump 2| through a belt 41 and the condensate pump 33 through a belt 48.

In operation, the food products to be frozen or cooled are placed in the container II on the shelves ii and the cover it secured to the container II by means of the wing nuts II to form a pressure tight vessel. The switch I4 is closed to start the motor ll which simultaneously operatec the air pump II, the centrifugal compressorli, and the condensate pump 33. At first the air pump removes the air from the container ll. When moisture evaporates from the products contained in the'container II, the gases flowing through the pipe I! will contain a large per- ,several minutes required under conventional methods of freezing foods.

In Figure 2 is shown a device which may be employed to cool or freeze food products contained in an ordinary vessel suchas is used in the home. It is to be understood however, that direction.

bowed upwardly in the middle is secured at its periphery to the plate I}. The diaphragm 'II is' provided with a check valve 01 which prevents .this device could be made in any size. Food products 55 containing water in their composition are placed in a container It. The device employed for removing a percentage of the moisture from the food products to cool them is generally illustrated at 58. A flat plate II which is covered by a gasket I on its lower face is placed in contact with the container II. The gasket I is of substantial area so that a pressure-tight seal may be made with containers of various sizes. The gasket 60. is provided with an opening 82 at the center thereof. The plate 5! has an oii'set portion 64 at its center which serves to support a cylinder 86 at right angles to the plate It. A flat disk 51 having a lower surface 68 of resilient material normally rests on the top surface of the ofiset portion 64 of the plate 5! and covers an opening ll therein.

Slidably carried by the interior of the cylind I6 is a second cylindrical member II. A gasket ll serves as a sealing ring between the cylinders 86 and H. The gasket 13 is of the type adapted to prevent the passage. of fluids in a downward direction as seen in the drawings. The cylinder 6 is provided at its uppermost edge with tumedin portions I! to guide the cylinder ll: Likewise, the cylinder Ii is provided with tumed-out portions it to guide the lower portion of the cylinder II. The lower portion of the cylinder Ii is provided with an opening II which is covered by a disk It. The disk II has alower surface ll of resilient material to form a tight seal against the lower portion of the cylinder ll.

vided with an outwardly extending flat portion 83 which serves as the upper abutment for a spring 85. The lower abutment for the spring I! is provided by the plate It.

In operation, food products are placed in the container 5 and the device it is placed over the containerin such a manner that the gasket O! forms a pressure tight seal therewith. Normally, I

I cylinder 'II is increased so that the pressure below the disc I! will offset that above it to raise the disk it slightly. permitting the gases to escape. When the pressure applied to the flat portion It is removed, the spring I! will again raise the cylinder 'II to reduce the pressure below it. The pressure within the container '8 will then be suillcient to raise the disk 81, permitting air andmoisture to flow therefrom. It will be seen that repeated actuation of the cylinder II will result in lowering of the pressure within the container 56 to vaporize the moisture contained in the food products and cause cooling of these products.

A rather simple form of product cooler is shown in Figure 3. Any product ll containing moisture I is placed in a container I which is covered by a pumping device 92. A plate M is provided with a gasket 94 on its lower surface to form a pressure tight seal between the plate 03 and the container ii. The plate 93 is provided with a check valve 95 which permits the passage of gases from the container Ii to the space above it but will not permit the passage of gases in the opposite A flexible ,diaphragm l which is the flow of air from the surrounding atmosfliere into the space between the diaphragm It and the plate 93.

The operation of this device is as follows. The diaphragm it is alternately depressed and released which results in pumping of gases from the container ii to the surrounding atmosphere.

when the diaphragm is depressed the check valve 01 moves upwardly to permit the escape of gas from the space between the diaphragm I. and the plate 03. when the diaphragm is released check valve 91 closes and check valve ll opens to permit gases to pass from the container. Repeated operations will lower the pressure within the container 9| which will result in vaporization oi the moisture contained in the food product as. This will result in coollng or freezing of the product 0..

Thus it will be seen that I have provided a novel method of cooling and freezing products containing moisture in their composition. It is to be understood that I am notto be limited by the specific disclosure but only by the scope of the appended claims.

The upper extremity of the cylinder 1! is pro- 76 I claim as my invention: 1. In a device for cooling products, in combination, a relatively stationary member adapted reciprocable member secured to said stationary member and forming an enclosed space between said two members, a check valve in said stationary member for preventing flow of gases into the container but permitting flow of gases from the I valve in said reciprocable member preventing container, and a check valve in said reciprocable member for preventing flow of gases into the space between said two members.

2. In a device for cooling products, in combination, a relatively stationary'member adapted to cooperate with a container for products containing' volatile constituents to close an opening therein and form a pressure tight seal therewith,

a cylinder mounted on said member, a recipro-' cable member slidably mounted with respect to said cylinder and forming an inclosed space'together with said stationary member and said cylinder, a first check valve in said stationary member preventing flow of gases into the container but permitting flow of gases from the container into the inclosed space, and a second check valve in said reciprocable member preventing flow of gases from the atmosphere to the inclosed space but permitting flow of gases from the inclosed space to the atmosphere, whereby successive movements of said reciprocable member will cause a lowering of the pressure within the container causing vaporization of volatile liquids in products contained therein.

3. In a device for cooling products, in combination, a relatively flat stationary member.

adapted to cooperate with a container for products containing volatile constituents to close an opening therein and form a pressure tight seal therewith, a cylinder mounted on said stationary member and relativelyperpendicularly thereto, a

reciprooable member slidably mounted with respect to said cylinder and forming an inclosed space together with said stationary memberand said cylinder, 9. spring operating on said stationary member and on said reciprocable member tending to increase the volume in the inclosed space, a first check valve in said stationary member preventing flow of gases into the container but permitting flow of gases from the container into the inclosed space, and a second check flow of gases from the atmosphere to the inclosed space but permitting flow of gases from the in closed space to the atmosphere, whereby successive movements of said rec'iprocable member will cause a lowering of the pressure withinthe container causing vaporization of volatile liquids in the products contained therein.

4. In a device for cooling products, in combimember and on said reciprocable member tend ing to increase the volume in the inclosed space, a check valve in said stationary member preventing flow of gases into the container but permitting flow of gases from the container through said member, and a gasket between said cylinder and said reciprocable member, said gasket being adapted to prevent flow of air into the inclosed space when the pressure therein is below atmospheric pressure.

5-. In a device for cooling products, in combination, a relatively stationary member adapted to cooperate with a container for products com taining volatile constituents to close an opening therein and form a pressure tight seal therewith, I

a flexible diaphragm fastened at its edges to said stationary member and forming an enclosed space in conjunction with said stationary memher, said diaphragm being adapted by manual manipulation to vary the volume of the enclosed space, and checkvalves in said member and in v said diaphragm for preventing the flow of gases into the container, but permitting flow of gases out of the container and the enclosed space.

= ALWIN B. NEWTON. 

